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HIGH-RESOLUTION EPR SPECTROSCOPY OF MO ENZYMES. SULFITE OXIDASES: STRUCTURAL AND FUNCTIONAL IMPLICATIONS. mo酶的高分辨率epr光谱。亚硫酸盐氧化酶:结构和功能意义。

Biological magnetic resonance Pub Date : 2010-01-01 DOI: 10.1007/978-1-4419-1139-1_6

John H Enemark, A V Astashkin, A M Raitsimring

{"title":"HIGH-RESOLUTION EPR SPECTROSCOPY OF MO ENZYMES. SULFITE OXIDASES: STRUCTURAL AND FUNCTIONAL IMPLICATIONS.","authors":"John H Enemark, A V Astashkin, A M Raitsimring","doi":"10.1007/978-1-4419-1139-1_6","DOIUrl":"https://doi.org/10.1007/978-1-4419-1139-1_6","url":null,"abstract":"Sulfite oxidases (SOs) are physiologically vital Mo-containing enzymes that occur in animals, plants, and bacteria and which catalyze the oxidation of sulfite to sulfate, the terminal reaction in the oxidative degradation of sulfur-containing compounds. X-ray structure determinations of SOs from several species show nearly identical coordination structures of the molybdenum active center, and a common catalytic mechanism has been proposed that involves the generation of a transient paramagnetic Mo(V) state through a series of coupled electron-proton transfer steps. This chapter describes the use of pulsed electron-nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM) spectroscopic techniques to obtain information about the structure of this Mo(V) species from the hyperfine interactions (hfi) and nuclear quadrupole interactions (nqi) of nearby magnetic nuclei. Variable frequency instrumentation is essential to optimize the experimental conditions for measuring the couplings of different types of nuclei (e.g., (1)H, (2)H, (31)P, and (17)O). The theoretical background necessary for understanding the ESEEM and ENDOR spectra of the Mo(V) centers of SOs is outlined, and examples of the use of advanced pulsed EPR methods (RP-ESEEM, HYSCORE, integrated four-pulse ESEEM) for structure determination are presented. The analysis of variable-frequency pulsed EPR data from SOs is aided by parallel studies of model compounds that contain key functional groups or that are isotopically labeled and thus provide benchmark data for enzymes. Enormous progress has been made on the use of high-resolution variable-frequency pulsed EPR methods to investigate the structures and mechanisms of SOs during the past ~15 years, and the future is bright for the continued development and application of this technology to SOs, other molybdenum enzymes, and other problems in metallobiochemistry.","PeriodicalId":88834,"journal":{"name":"Biological magnetic resonance","volume":"29 2","pages":"121-168"},"PeriodicalIF":0.0,"publicationDate":"2010-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-1-4419-1139-1_6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"29639646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

EPR of Mononuclear Non-Heme Iron Proteins. 单核非血红素铁蛋白的EPR。

Biological magnetic resonance Pub Date : 2009-06-19 DOI: 10.1007/978-0-387-84856-3_6

B. J. Gaffney

引用次数: 15

EPR of Mononuclear Non-Heme Iron Proteins. 单核非血红素铁蛋白的EPR。

Biological magnetic resonance Pub Date : 2009-06-19 DOI: 10.1007/978-0-387-84856-3

Betty J Gaffney

{"title":"EPR of Mononuclear Non-Heme Iron Proteins.","authors":"Betty J Gaffney","doi":"10.1007/978-0-387-84856-3","DOIUrl":"https://doi.org/10.1007/978-0-387-84856-3","url":null,"abstract":"Flexible geometry of three- to six-protein side-chain ligands to non-heme iron in proteins is the basis for widely diverse reactivites ranging from iron transport to redox chemistry. The gap between fixed states determined by x-ray analysis can be filled by spectroscopic study of trapped intermediates. EPR is a versatile and relatively quick approach to defining intermediate states in terms of the geometry and electronic structures of iron. A number of examples in which the iron chemistry of non-heme proteins is understood through x-ray structures at subbond length resolution, refined calculations, and spectroscopy exist now. Some examples in which EPR has provided unique insight are summarized in Table 1. Assignment and quantitative evaluation of the EPR resonances in ferric, non-heme iron sites is the focus of the first section of this review. An earlier chapter in this series provides more background on the theory specific to EPR of S = 5/2 metal ions [1]. Besides EPR spectra of ferric mononuclear sites, EPR of ferrous iron coupled to a spin 1/2 radical, as it pertains to the categories mononuclear and non-heme, will also be covered, in the second half of this chapter. Examples include the quinone-ferrous interactions in photosynthetic reaction centers and nitric oxide complexes with non-heme ferrous iron. Other recent reviews of the biochemistry and spectroscopy of non-heme iron proteins provide additional background [2-6].","PeriodicalId":88834,"journal":{"name":"Biological magnetic resonance","volume":"28 ","pages":"233-268"},"PeriodicalIF":0.0,"publicationDate":"2009-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1007/978-0-387-84856-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"28951689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 42